<template>
  <div class="shopcart">
    <div class="content" @click="toggleList">
      <div class="content-left">
        <div class="logo-wrapper">
          <div class="logo" :class="{'highlight':totalCount>0}">
            <span class="icon-shopping_cart" v-if="totalCount<=0">
              <img src="~/assets/images/cart.svg" alt="">
            </span>
            <span class="icon-shopping_cart highlight" v-else>
              <img src="~/assets/images/cart2.svg" alt="">
            </span>
          </div>
          <div class="num" v-show="totalCount>0">{{totalCount}}</div>
        </div>
        <div class="price" :class="{'highlight':totalPrice>0}">￥{{totalPrice}}元</div>
        <div class="desc">另需配送费￥{{deliveryPrice}}元</div>
      </div>
      <div class="content-right">
        <div class="pay" :class="payClass">{{payDesc}}</div>
      </div>
    </div>
    <div class="ball-container">
      <div v-for="(ball, index) in balls" :key="index">
        <transition name="drop" @before-enter="beforeDrop" @enter="dropping" @after-enter="afterDrop">
          <div class="ball" v-show="ball.show">
            <div class="inner inner-hook"></div>
          </div>
        </transition>
      </div>
    </div>
    <div class="mark" v-show="listShow" @click="toggleList"></div>
    <transition name="fold">
      <div class="shopcart-list" v-show="listShow">
        <div class="list-header">
          <h1 class="title">已选商品</h1>
          <span class="empty" @click="empty">清空</span>
        </div>
        <div class="list-content" ref="listContent">
          <ul>
            <li class="food" v-for="(food, index) in selectFoods" :key="index">
              <span class="name">{{food.name}}</span>
              <div class="price">
                <span>￥{{food.price*food.count}}</span>
              </div>
              <div class="cartcontrol-wrapper">
                <cartcontrol @add="addFood" :food="food"></cartcontrol>
              </div>
            </li>
          </ul>
        </div>
      </div>
    </transition>
  </div>
</template>

<script>
import cartcontrol from "./cartcontrol";

export default {
  props: {
    selectFoods: {
      type: Array,
      default() {
        return [];
      }
    },
    deliveryPrice: {
      type: Number,
      default: 0
    },
    minPrice: {
      type: Number,
      default: 0
    }
  },

  data() {
    return {
      balls: [
        {
          show: false
        },
        {
          show: false
        },
        {
          show: false
        },
        {
          show: false
        },
        {
          show: false
        }
      ],
      dropBalls: [],
      fold: true
    };
  },

  computed: {
    totalPrice() {
      let total = 0;
      this.selectFoods.forEach(food => {
        total += food.price * food.count;
      });
      return total;
    },
    totalCount() {
      let count = 0;
      this.selectFoods.forEach(food => {
        count += food.count;
      });
      return count;
    },
    payDesc() {
      if (this.totalPrice === 0) {
        return `¥${this.minPrice}元起送`;
      } else if (this.totalPrice < this.minPrice) {
        let diff = this.minPrice - this.totalPrice;
        return `还差¥${diff}元起送`;
      } else {
        return "去结算";
      }
    },
    payClass() {
      if (this.totalPrice < this.minPrice) {
        return "not-enough";
      } else {
        return "enough";
      }
    },
    listShow() {
      if (!this.totalCount) {
        return false;
      }
      return !this.fold;
    }
  },

  methods: {
    toggleList() {
      if (!this.totalCount) {
        return;
      }
      this.fold = !this.fold;
    },
    hideList() {
      this.fold = true;
    },
    empty() {
      this.selectFoods.forEach(food => {
        food.count = 0;
      });
    },
    pay() {
      if (this.totalPrice < this.minPrice) {
        return;
      }
      window.alert(`支付${this.totalPrice}元`);
    },
    addFood(target) {
      this.drop(target);
    },

    drop(el) {
      for (let i = 0; i < this.balls.length; i++) {
        let ball = this.balls[i];
        if (!ball.show) {
          ball.show = true;
          ball.el = el;
          this.dropBalls.push(ball);
          return;
        }
      }
    },
    beforeDrop(el) {
      let count = this.balls.length;
      while (count--) {
        let ball = this.balls[count];
        if (ball.show) {
          let rect = ball.el.getBoundingClientRect();
          let x = rect.left - 32;
          let y = -(window.innerHeight - rect.top - 22);
          el.style.display = "";
          el.style.webkitTransform = `translate3d(0,${y}px,0)`;
          el.style.transform = `translate3d(0,${y}px,0)`;
          let inner = el.getElementsByClassName("inner-hook")[0];
          inner.style.webkitTransform = `translate3d(${x}px,0,0)`;
          inner.style.transform = `translate3d(${x}px,0,0)`;
        }
      }
    },
    dropping(el, done) {
      let rf = el.offsetHeight;
      this.$nextTick(() => {
        el.style.webkitTransform = "translate3d(0,0,0)";
        el.style.transform = "translate3d(0,0,0)";
        let inner = el.getElementsByClassName("inner-hook")[0];
        inner.style.webkitTransform = "translate3d(0,0,0)";
        inner.style.transform = "translate3d(0,0,0)";
        el.addEventListener("transitionend", done);
      });
    },
    afterDrop(el) {
      let ball = this.dropBalls.shift();
      if (ball) {
        ball.show = false;
        el.style.display = "none";
      }
    }
  },
  components: {
    cartcontrol
  }
};
</script>

<style lang="scss">
.shopcart {
  position: fixed;
  left: 0;
  bottom: 0;
  z-index: 50;
  width: 100%;
  height: 48px;
  background: #000;

  .content {
    display: flex;
    background: rgba(61, 61, 63, 0.9);
    font-size: 0;
    color: rgba(255, 255, 255, 0.4);

    .content-left {
      flex: 1;

      .logo-wrapper {
        display: inline-block;
        vertical-align: top;
        position: relative;
        top: -10px;
        margin: 0 12px;
        padding: 6px;
        width: 56px;
        height: 56px;
        box-sizing: border-box;
        border-radius: 50%;
        background-image: radial-gradient(circle, #363636 6.266667vw, #444 0);

        .logo {
          width: 100%;
          height: 100%;
          border-radius: 50%;
          text-align: center;
          background: #2b343c;

          &.highlight {
            background: rgb(0, 160, 220);
          }

          .icon-shopping_cart {
            margin: 0 auto;
            padding: 20% 0;
            display: block;
            width: 60%;
            height: 60%;
            color: #80858a;
          }
        }

        .num {
          position: absolute;
          top: 0;
          right: 0;
          width: 24px;
          height: 16px;
          line-height: 16px;
          text-align: center;
          border-radius: 16px;
          font-size: 9px;
          font-weight: 700;
          color: #ffffff;
          box-shadow: 0px 4px 8px 0 rgba(0, 0, 0, 0.4);
          background-image: linear-gradient(-90deg, #ff7416, #ff3c15 98%);
        }
      }

      .price {
        display: inline-block;
        vertical-align: top;
        margin-top: 12px;
        line-height: 24px;
        padding-right: 12px;
        box-sizing: border-box;
        border-right: 1px solid rgba(255, 255, 255, 0.1);
        font-size: 16px;
        font-weight: 700;

        &.highlight {
          color: #fff;
        }
      }

      .desc {
        display: inline-block;
        vertical-align: top;
        margin: 12px 0 0 12px;
        line-height: 24px;
        font-size: 10px;
      }
    }

    .content-right {
      flex: 0 0 105px;
      width: 105px;

      .pay {
        height: 48px;
        line-height: 48px;
        text-align: center;
        font-size: 14px;
        font-weight: 700;

        &.not-enough {
          color: #fff;
        }

        &.enough {
          background: #00b43c;
          color: #fff;
        }
      }
    }
  }

  .ball-container {
    .ball {
      position: fixed;
      left: 32px;
      bottom: 22px;
      z-index: 200;

      &.drop-transition {
        transition: all 0.4s cubic-bezier(0.49, -0.29, 0.75, 0.41);

        .inner {
          width: 16px;
          height: 16px;
          border-radius: 50%;
          background: rgb(0, 160, 220);
          transition: all 0.4s;
        }
      }
    }
  }

  .mark {
    position: fixed;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4);
    z-index: -2;
  }

  .shopcart-list {
    position: absolute;
    left: 0;
    top: 0;
    z-index: -1;
    width: 100%;
    transform: translate3d(0, -100%, 0);

    &.fold-enter-active,
    &.fold-leave-active {
      transition: all 0.5s;
    }

    &.fold-enter,
    &.fold-leave-active {
      transform: translate3d(0, 0, 0);
    }

    .list-header {
      height: 40px;
      line-height: 40px;
      padding: 0 18px;
      background: #f3f5f7;
      border-bottom: 1px solid rgba(7, 17, 27, 0.1);

      .title {
        float: left;
        font-size: 14px;
        color: rgb(7, 17, 27);
      }

      .empty {
        float: right;
        font-size: 12px;
        color: rgb(0, 160, 220);
      }
    }

    .list-content {
      padding: 0 18px;
      max-height: 217px;
      overflow: hidden;
      background: #fff;

      .food {
        display: flex;
        align-items: center;
        position: relative;
        padding: 12px 0;
        box-sizing: border-box;
        position: relative;
        &:after {
          display: block;
          position: absolute;
          left: 0;
          bottom: 0;
          width: 100%;
          border: 1px solid rgba(7, 17, 27, 0.1);
          content: " ";
        }
        .name {
          line-height: 24px;
          font-size: 14px;
          color: rgb(7, 17, 27);
        }

        .price {
          position: absolute;
          right: 90px;
          bottom: 12px;
          line-height: 24px;
          font-size: 14px;
          font-weight: 700;
          color: rgb(240, 20, 20);
        }

        .cartcontrol-wrapper {
          position: absolute;
          right: 0;
        }
      }
    }
  }
}
</style>
